First Bulgarian Empire

The First Bulgarian Empire (Old Bulgarian: ц︢рьство бл︢гарское, ts'rstvo bl'garskoe) was a medieval Bulgarian Empire that existed in South Eastern Europe between the 7th and 11th centuries AD. It was founded in 681 when Bulgar tribes led by Asparuh moved to the northeastern Balkans. There they secured Byzantine recognition of their right to settle south of the Danube by defeating – possibly with the help of local South Slavic tribes – the Byzantine army led by Constantine IV. At the height of its power, Bulgaria spread from the Danube Bend to the Black Sea and from the Dnieper River to the Adriatic Sea.

HISTORY
As the state solidified its position in the Balkans, it entered into a centuries-long interaction, sometimes friendly and sometimes hostile, with the Byzantine Empire. Bulgaria emerged as Byzantium's chief antagonist to its north, resulting in several wars. The two powers also enjoyed periods of peace and alliance, most notably during the Second Arab siege of Constantinople, where the Bulgarian army broke the siege and destroyed the Arab army, thus preventing an Arab invasion of South Eastern Europe. Byzantium had a strong cultural influence on Bulgaria,which also led to the eventual adoption of Christianity in 864. After the disintegration of the Avar Khaganate, the country expanded its territory northwest to the Pannonian Plain. Later the Bulgarians confronted the advance of the Pechenegs and Cumans, and achieved a decisive victory over the Magyars, forcing them to establish themselves permanently in Pannonia.

During the late 9th and early 10th centuries, Simeon I achieved a string of victories over the Byzantines. Thereafter, he was recognized with the title of Emperor, and proceeded to expand the state to its greatest extent. After the annihilation of the Byzantine army in the battle of Anchialus in 917, the Bulgarians laid siege to Constantinople in 923 and 924. The Byzantines, however, eventually recovered, and in 1014, under Basil II, inflicted a crushing defeat on the Bulgarians at the Battle of Kleidion. By 1018, the last Bulgarian strongholds had surrendered to the Byzantine Empire, and the First Bulgarian Empire had ceased to exist.It was succeeded by the Second Bulgarian Empire in 1185.

After the adoption of Christianity, Bulgaria became the cultural center of Slavic Europe. Its leading cultural position was further consolidated with the invention of the Glagolitic and Early Cyrillic alphabets shortly after in the capital Preslav, and literature produced in Old Bulgarian soon began spreading north. Old Bulgarian became the lingua franca of much of Eastern Europe and it came to be known as Old Church Slavonic. In 927, the fully independent Bulgarian Patriarchy was officially recognized.

The ruling Bulgars and other non-Slavic tribes in the empire gradually mixed and adopted the prevailing Slavic language, thus gradually forming the Bulgarian nation from the 7th century to the 9th century. Since the late 9th century, the names Bulgarians and Bulgariangained prevalence and became permanent designations for the local population, both in literature and in common parlance. The development of Old Church Slavonic literacy had the effect of preventing the assimilation of the South Slavs into neighbouring cultures,while stimulating the formation of a distinct Bulgarian identity.